diff options
Diffstat (limited to 'drivers/vfio/pci/vfio_pci.c')
-rw-r--r-- | drivers/vfio/pci/vfio_pci.c | 390 |
1 files changed, 366 insertions, 24 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 379a02c36e37..6c6b37b5c04e 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -9,7 +9,6 @@ */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt -#define dev_fmt pr_fmt #include <linux/device.h> #include <linux/eventfd.h> @@ -54,6 +53,12 @@ module_param(disable_idle_d3, bool, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(disable_idle_d3, "Disable using the PCI D3 low power state for idle, unused devices"); +static bool enable_sriov; +#ifdef CONFIG_PCI_IOV +module_param(enable_sriov, bool, 0644); +MODULE_PARM_DESC(enable_sriov, "Enable support for SR-IOV configuration. Enabling SR-IOV on a PF typically requires support of the userspace PF driver, enabling VFs without such support may result in non-functional VFs or PF."); +#endif + static inline bool vfio_vga_disabled(void) { #ifdef CONFIG_VFIO_PCI_VGA @@ -466,6 +471,44 @@ out: vfio_pci_set_power_state(vdev, PCI_D3hot); } +static struct pci_driver vfio_pci_driver; + +static struct vfio_pci_device *get_pf_vdev(struct vfio_pci_device *vdev, + struct vfio_device **pf_dev) +{ + struct pci_dev *physfn = pci_physfn(vdev->pdev); + + if (!vdev->pdev->is_virtfn) + return NULL; + + *pf_dev = vfio_device_get_from_dev(&physfn->dev); + if (!*pf_dev) + return NULL; + + if (pci_dev_driver(physfn) != &vfio_pci_driver) { + vfio_device_put(*pf_dev); + return NULL; + } + + return vfio_device_data(*pf_dev); +} + +static void vfio_pci_vf_token_user_add(struct vfio_pci_device *vdev, int val) +{ + struct vfio_device *pf_dev; + struct vfio_pci_device *pf_vdev = get_pf_vdev(vdev, &pf_dev); + + if (!pf_vdev) + return; + + mutex_lock(&pf_vdev->vf_token->lock); + pf_vdev->vf_token->users += val; + WARN_ON(pf_vdev->vf_token->users < 0); + mutex_unlock(&pf_vdev->vf_token->lock); + + vfio_device_put(pf_dev); +} + static void vfio_pci_release(void *device_data) { struct vfio_pci_device *vdev = device_data; @@ -473,6 +516,7 @@ static void vfio_pci_release(void *device_data) mutex_lock(&vdev->reflck->lock); if (!(--vdev->refcnt)) { + vfio_pci_vf_token_user_add(vdev, -1); vfio_spapr_pci_eeh_release(vdev->pdev); vfio_pci_disable(vdev); } @@ -498,6 +542,7 @@ static int vfio_pci_open(void *device_data) goto error; vfio_spapr_pci_eeh_open(vdev->pdev); + vfio_pci_vf_token_user_add(vdev, 1); } vdev->refcnt++; error: @@ -1140,6 +1185,65 @@ hot_reset_release: return vfio_pci_ioeventfd(vdev, ioeventfd.offset, ioeventfd.data, count, ioeventfd.fd); + } else if (cmd == VFIO_DEVICE_FEATURE) { + struct vfio_device_feature feature; + uuid_t uuid; + + minsz = offsetofend(struct vfio_device_feature, flags); + + if (copy_from_user(&feature, (void __user *)arg, minsz)) + return -EFAULT; + + if (feature.argsz < minsz) + return -EINVAL; + + /* Check unknown flags */ + if (feature.flags & ~(VFIO_DEVICE_FEATURE_MASK | + VFIO_DEVICE_FEATURE_SET | + VFIO_DEVICE_FEATURE_GET | + VFIO_DEVICE_FEATURE_PROBE)) + return -EINVAL; + + /* GET & SET are mutually exclusive except with PROBE */ + if (!(feature.flags & VFIO_DEVICE_FEATURE_PROBE) && + (feature.flags & VFIO_DEVICE_FEATURE_SET) && + (feature.flags & VFIO_DEVICE_FEATURE_GET)) + return -EINVAL; + + switch (feature.flags & VFIO_DEVICE_FEATURE_MASK) { + case VFIO_DEVICE_FEATURE_PCI_VF_TOKEN: + if (!vdev->vf_token) + return -ENOTTY; + + /* + * We do not support GET of the VF Token UUID as this + * could expose the token of the previous device user. + */ + if (feature.flags & VFIO_DEVICE_FEATURE_GET) + return -EINVAL; + + if (feature.flags & VFIO_DEVICE_FEATURE_PROBE) + return 0; + + /* Don't SET unless told to do so */ + if (!(feature.flags & VFIO_DEVICE_FEATURE_SET)) + return -EINVAL; + + if (feature.argsz < minsz + sizeof(uuid)) + return -EINVAL; + + if (copy_from_user(&uuid, (void __user *)(arg + minsz), + sizeof(uuid))) + return -EFAULT; + + mutex_lock(&vdev->vf_token->lock); + uuid_copy(&vdev->vf_token->uuid, &uuid); + mutex_unlock(&vdev->vf_token->lock); + + return 0; + default: + return -ENOTTY; + } } return -ENOTTY; @@ -1278,6 +1382,150 @@ static void vfio_pci_request(void *device_data, unsigned int count) mutex_unlock(&vdev->igate); } +static int vfio_pci_validate_vf_token(struct vfio_pci_device *vdev, + bool vf_token, uuid_t *uuid) +{ + /* + * There's always some degree of trust or collaboration between SR-IOV + * PF and VFs, even if just that the PF hosts the SR-IOV capability and + * can disrupt VFs with a reset, but often the PF has more explicit + * access to deny service to the VF or access data passed through the + * VF. We therefore require an opt-in via a shared VF token (UUID) to + * represent this trust. This both prevents that a VF driver might + * assume the PF driver is a trusted, in-kernel driver, and also that + * a PF driver might be replaced with a rogue driver, unknown to in-use + * VF drivers. + * + * Therefore when presented with a VF, if the PF is a vfio device and + * it is bound to the vfio-pci driver, the user needs to provide a VF + * token to access the device, in the form of appending a vf_token to + * the device name, for example: + * + * "0000:04:10.0 vf_token=bd8d9d2b-5a5f-4f5a-a211-f591514ba1f3" + * + * When presented with a PF which has VFs in use, the user must also + * provide the current VF token to prove collaboration with existing + * VF users. If VFs are not in use, the VF token provided for the PF + * device will act to set the VF token. + * + * If the VF token is provided but unused, an error is generated. + */ + if (!vdev->pdev->is_virtfn && !vdev->vf_token && !vf_token) + return 0; /* No VF token provided or required */ + + if (vdev->pdev->is_virtfn) { + struct vfio_device *pf_dev; + struct vfio_pci_device *pf_vdev = get_pf_vdev(vdev, &pf_dev); + bool match; + + if (!pf_vdev) { + if (!vf_token) + return 0; /* PF is not vfio-pci, no VF token */ + + pci_info_ratelimited(vdev->pdev, + "VF token incorrectly provided, PF not bound to vfio-pci\n"); + return -EINVAL; + } + + if (!vf_token) { + vfio_device_put(pf_dev); + pci_info_ratelimited(vdev->pdev, + "VF token required to access device\n"); + return -EACCES; + } + + mutex_lock(&pf_vdev->vf_token->lock); + match = uuid_equal(uuid, &pf_vdev->vf_token->uuid); + mutex_unlock(&pf_vdev->vf_token->lock); + + vfio_device_put(pf_dev); + + if (!match) { + pci_info_ratelimited(vdev->pdev, + "Incorrect VF token provided for device\n"); + return -EACCES; + } + } else if (vdev->vf_token) { + mutex_lock(&vdev->vf_token->lock); + if (vdev->vf_token->users) { + if (!vf_token) { + mutex_unlock(&vdev->vf_token->lock); + pci_info_ratelimited(vdev->pdev, + "VF token required to access device\n"); + return -EACCES; + } + + if (!uuid_equal(uuid, &vdev->vf_token->uuid)) { + mutex_unlock(&vdev->vf_token->lock); + pci_info_ratelimited(vdev->pdev, + "Incorrect VF token provided for device\n"); + return -EACCES; + } + } else if (vf_token) { + uuid_copy(&vdev->vf_token->uuid, uuid); + } + + mutex_unlock(&vdev->vf_token->lock); + } else if (vf_token) { + pci_info_ratelimited(vdev->pdev, + "VF token incorrectly provided, not a PF or VF\n"); + return -EINVAL; + } + + return 0; +} + +#define VF_TOKEN_ARG "vf_token=" + +static int vfio_pci_match(void *device_data, char *buf) +{ + struct vfio_pci_device *vdev = device_data; + bool vf_token = false; + uuid_t uuid; + int ret; + + if (strncmp(pci_name(vdev->pdev), buf, strlen(pci_name(vdev->pdev)))) + return 0; /* No match */ + + if (strlen(buf) > strlen(pci_name(vdev->pdev))) { + buf += strlen(pci_name(vdev->pdev)); + + if (*buf != ' ') + return 0; /* No match: non-whitespace after name */ + + while (*buf) { + if (*buf == ' ') { + buf++; + continue; + } + + if (!vf_token && !strncmp(buf, VF_TOKEN_ARG, + strlen(VF_TOKEN_ARG))) { + buf += strlen(VF_TOKEN_ARG); + + if (strlen(buf) < UUID_STRING_LEN) + return -EINVAL; + + ret = uuid_parse(buf, &uuid); + if (ret) + return ret; + + vf_token = true; + buf += UUID_STRING_LEN; + } else { + /* Unknown/duplicate option */ + return -EINVAL; + } + } + } + + ret = vfio_pci_validate_vf_token(vdev, vf_token, &uuid); + if (ret) + return ret; + + return 1; /* Match */ +} + static const struct vfio_device_ops vfio_pci_ops = { .name = "vfio-pci", .open = vfio_pci_open, @@ -1287,10 +1535,40 @@ static const struct vfio_device_ops vfio_pci_ops = { .write = vfio_pci_write, .mmap = vfio_pci_mmap, .request = vfio_pci_request, + .match = vfio_pci_match, }; static int vfio_pci_reflck_attach(struct vfio_pci_device *vdev); static void vfio_pci_reflck_put(struct vfio_pci_reflck *reflck); +static struct pci_driver vfio_pci_driver; + +static int vfio_pci_bus_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct vfio_pci_device *vdev = container_of(nb, + struct vfio_pci_device, nb); + struct device *dev = data; + struct pci_dev *pdev = to_pci_dev(dev); + struct pci_dev *physfn = pci_physfn(pdev); + + if (action == BUS_NOTIFY_ADD_DEVICE && + pdev->is_virtfn && physfn == vdev->pdev) { + pci_info(vdev->pdev, "Captured SR-IOV VF %s driver_override\n", + pci_name(pdev)); + pdev->driver_override = kasprintf(GFP_KERNEL, "%s", + vfio_pci_ops.name); + } else if (action == BUS_NOTIFY_BOUND_DRIVER && + pdev->is_virtfn && physfn == vdev->pdev) { + struct pci_driver *drv = pci_dev_driver(pdev); + + if (drv && drv != &vfio_pci_driver) + pci_warn(vdev->pdev, + "VF %s bound to driver %s while PF bound to vfio-pci\n", + pci_name(pdev), drv->name); + } + + return 0; +} static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) { @@ -1302,12 +1580,12 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) return -EINVAL; /* - * Prevent binding to PFs with VFs enabled, this too easily allows - * userspace instance with VFs and PFs from the same device, which - * cannot work. Disabling SR-IOV here would initiate removing the - * VFs, which would unbind the driver, which is prone to blocking - * if that VF is also in use by vfio-pci. Just reject these PFs - * and let the user sort it out. + * Prevent binding to PFs with VFs enabled, the VFs might be in use + * by the host or other users. We cannot capture the VFs if they + * already exist, nor can we track VF users. Disabling SR-IOV here + * would initiate removing the VFs, which would unbind the driver, + * which is prone to blocking if that VF is also in use by vfio-pci. + * Just reject these PFs and let the user sort it out. */ if (pci_num_vf(pdev)) { pci_warn(pdev, "Cannot bind to PF with SR-IOV enabled\n"); @@ -1320,8 +1598,8 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); if (!vdev) { - vfio_iommu_group_put(group, &pdev->dev); - return -ENOMEM; + ret = -ENOMEM; + goto out_group_put; } vdev->pdev = pdev; @@ -1332,18 +1610,27 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) INIT_LIST_HEAD(&vdev->ioeventfds_list); ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev); - if (ret) { - vfio_iommu_group_put(group, &pdev->dev); - kfree(vdev); - return ret; - } + if (ret) + goto out_free; ret = vfio_pci_reflck_attach(vdev); - if (ret) { - vfio_del_group_dev(&pdev->dev); - vfio_iommu_group_put(group, &pdev->dev); - kfree(vdev); - return ret; + if (ret) + goto out_del_group_dev; + + if (pdev->is_physfn) { + vdev->vf_token = kzalloc(sizeof(*vdev->vf_token), GFP_KERNEL); + if (!vdev->vf_token) { + ret = -ENOMEM; + goto out_reflck; + } + + mutex_init(&vdev->vf_token->lock); + uuid_gen(&vdev->vf_token->uuid); + + vdev->nb.notifier_call = vfio_pci_bus_notifier; + ret = bus_register_notifier(&pci_bus_type, &vdev->nb); + if (ret) + goto out_vf_token; } if (vfio_pci_is_vga(pdev)) { @@ -1369,16 +1656,39 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) } return ret; + +out_vf_token: + kfree(vdev->vf_token); +out_reflck: + vfio_pci_reflck_put(vdev->reflck); +out_del_group_dev: + vfio_del_group_dev(&pdev->dev); +out_free: + kfree(vdev); +out_group_put: + vfio_iommu_group_put(group, &pdev->dev); + return ret; } static void vfio_pci_remove(struct pci_dev *pdev) { struct vfio_pci_device *vdev; + pci_disable_sriov(pdev); + vdev = vfio_del_group_dev(&pdev->dev); if (!vdev) return; + if (vdev->vf_token) { + WARN_ON(vdev->vf_token->users); + mutex_destroy(&vdev->vf_token->lock); + kfree(vdev->vf_token); + } + + if (vdev->nb.notifier_call) + bus_unregister_notifier(&pci_bus_type, &vdev->nb); + vfio_pci_reflck_put(vdev->reflck); vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev); @@ -1427,16 +1737,48 @@ static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev, return PCI_ERS_RESULT_CAN_RECOVER; } +static int vfio_pci_sriov_configure(struct pci_dev *pdev, int nr_virtfn) +{ + struct vfio_pci_device *vdev; + struct vfio_device *device; + int ret = 0; + + might_sleep(); + + if (!enable_sriov) + return -ENOENT; + + device = vfio_device_get_from_dev(&pdev->dev); + if (!device) + return -ENODEV; + + vdev = vfio_device_data(device); + if (!vdev) { + vfio_device_put(device); + return -ENODEV; + } + + if (nr_virtfn == 0) + pci_disable_sriov(pdev); + else + ret = pci_enable_sriov(pdev, nr_virtfn); + + vfio_device_put(device); + + return ret < 0 ? ret : nr_virtfn; +} + static const struct pci_error_handlers vfio_err_handlers = { .error_detected = vfio_pci_aer_err_detected, }; static struct pci_driver vfio_pci_driver = { - .name = "vfio-pci", - .id_table = NULL, /* only dynamic ids */ - .probe = vfio_pci_probe, - .remove = vfio_pci_remove, - .err_handler = &vfio_err_handlers, + .name = "vfio-pci", + .id_table = NULL, /* only dynamic ids */ + .probe = vfio_pci_probe, + .remove = vfio_pci_remove, + .sriov_configure = vfio_pci_sriov_configure, + .err_handler = &vfio_err_handlers, }; static DEFINE_MUTEX(reflck_lock); |